Cortisol is a hormone produced by the body, and is intimately involved with the adrenal and pituitary systems of the body. Normal levels of cortisol, when measured at the beginning of the day, are between 6 and 23 mcg/dL, though these numbers can rise and fall throughout the day. Abnormalities of the adrenal or pituitary glands, as well as some types of medication, can cause cortisol levels to drop. People with low cortisol can suffer from a range of potentially dangerous symptoms if left untreated. Synthetic steroid hormones can supplement low cortisol levels.
A lack of cortisol can make a person extremely tired and weak, according to the National Institutes of Health. Cortisol is produced as a response to the normal functioning of the pituitary glands. When the pituitary glands do not function properly, many of the body's functions become abnormal. Fatigue is a common symptom of many of these disorders, including glucose management, immune system response and thyroid hormone production.
Addison's disease is an adrenal gland disorder that may be indicated when a person's cortisol levels are low. The adrenal glands produce hormones that regulate glucose, potassium and sodium levels within the body and help the body respond appropriately to stress. People with Addison's disease do not produce enough hormones to oversee these functions. Gastrointestinal symptoms may be the marker of low cortisol in these cases, and include chronic diarrhea, vomiting, a loss of appetite and weight loss.
Low Blood Pressure
People who have low cortisol may also suffer from low blood pressure in response to the systemic lack of hormones. Low blood pressure can be a dangerous medical condition. People who have low blood pressure often feel lightheaded and dizzy and may injure themselves when suffering from falls relating to their health condition. Blood pressure levels more often than not revert to normal readings once cortisol is restored to the body.
Low cortisol levels that are caused by hypopituitarism, the underproduction of hormones by the pituitary gland, can lead to a host of sexual dysfunction and reproductive problems. The NIH reports that some of the common symptoms of hypopituitarism are a lack of sex drive in men and women and amenorrhea (lack of periods) in women of childbearing age. Women who are nursing and show a drop in cortisol may see a decrease in milk production. Infertility can be the result of low cortisol if hormone levels are not supplemented with medication.